1. Field of the Invention
The present invention generally relates to a speaker device, and more particularly to the speaker device used in a room.
2. Description of the Related Art
Conventionally, a speaker device includes of a plurality of speakers, as a speaker system. A multi-way speaker system is used widely in that each speaker outputs a sound signal divided into frequency bands by such as a low-pass filter, a middle-pass filter, and a high-pass filter.
It is possible to widely filter frequency bands reproducible by the speaker device, by outputting for every frequency band using a plurality of speakers.
A conventional speaker device will now be described with figures.
FIG. 1 is a diagram showing an example of a configuration of the conventional speaker device.
In the conventional speaker device 1 in FIG. 1, a loudspeaker unit 6 includes a woofer 3 (speaker for low-pitched sound), a squawker 4 (speaker for middle-pitched sound), and a tweeter 5 (speaker for-high-pitched sound) in an enclosure 2. And the woofer 3, a squawker 4, and the tweeter 5 are positioned on a baffle plate 7 (front wall). And a network is provided at the rear wall of the enclosure 2 to connect an input terminal for an amplifier connection with the loudspeaker unit 6.
Generally, two conventional speaker devices 1 are provided at a right side and a left side in that two loudspeaker units 6 are spaced and positioned at a predetermined distance so as to face a listener. A flow of a sound wave in the case in which the listener listens to sound from the conventional speaker device 1 installed in a room will now be explained with reference to FIG. 2.
FIG. 2 is a diagram showing an example of the flow of the sound wave from the conventional speaker device.
In FIG. 2, the conventional speaker device 1 is provided in a room, and the woofer 3, the squawker 4, and the tweeter 5 are directly positioned toward the listener 9.
Since the conventional speaker device 1 is a direct emission type, the listener 9 can obtain a feeling of an extent of a certain amount of sound.
However, although the sound wave output from the conventional speaker device 1 can obtain the feeling of an extent of sound, a rising of sound is slower. In order to improve a slowness of rising of the sound, a horn can be attached in each loudspeaker unit 6 of the conventional speaker device 1. However, if the horn is attached in the conventional speaker device 1, the feeling of the extent of the sound cannot be obtained.
Thus, the conventional speaker device 1 has a problem such that the feeling of the extent of the sound and a faster rising of the sound can not be realized at once.
FIG. 3 is a diagram showing an example of the responsibility of an impulse in a room.
Various sound waves such as a direct wave, an initial reflective wave, and a frequency reflective wave (reverberation) exist in space. The direct wave comes to the listener 9 in FIG. 2 first. And mainly since the initial reflective wave comes from both side walls, as compared with the direct wave, the initial reflective wave delays and comes to listener 9 at a wide angle. Moreover, the high order reflective wave randomly arrives at the listener 9 from various directions by being repeatedly reflected surrounding walls. Delay of the high order reflective wave causes a broad attenuation pattern, more than the initial reflective wave.
A complex combination in spatial three dimensions of the sound waves mentioned above gives the listener 9 the feeling of an extent of rich sound with a grand feeling of scale.
However, since a sound pressure of the direct sound from the loudspeaker unit 6 attached to a single planar baffle plate (front wall) 7 becomes higher in the conventional speaker device 1, compared with the initial reflective wave and a high order reflective wave, the sound pressure of direct sound masks sound by the initial reflective wave and the high order reflective wave. Moreover, since the direct wave, the initial reflective wave, and the high frequency reflective wave simultaneously reach the listener 9, the sound becomes monotony without a time difference.
Moreover, a multi-way speaker system such as the conventional speaker device 1 differs from systems where sound is output from one place, in that one musical sound and one voice are output from different speakers, respectively, and then the sound arrives at the listener 9. Thus, the listener 9 ends up listening to the sound as unnatural sound.
As described above, the conventional speaker device 1 cannot correctly reproduce original sound and sound field information.
FIG. 4 is a diagram showing an example of a directional sensitivity characteristic of the loudspeaker unit. A directional sensitivity characteristic indicates a frequency response at an angle off of a reference axis of the conventional speaker device 1. In FIG. 4, the directional sensitivity characteristic has angles of 0 degree, 30 degrees, and 60 degrees from a reference axis. At measurement points each of which is at an equal distance from a point on a reference axis, a result is shown in that each of the frequency responses is measured under the same condition.
Referring to FIG. 4, a sensitivity characteristic of each loudspeaker unit 6 is different for every directivity. If a frequency band is a higher sound range (higher pitched sound), the sensitivity in the angle out of the reference axis is deteriorated. On the other hand, since the frequency band is a higher sound range, the wavelength becomes shorter. Compared with other frequency bands, there is a larger amount of sound information in the simultaneous time domain. Considering this state, in order to reproduce the original sound and the sound field information without degrading the tone quality in the high-pitched sound range, a new speaker device is needed in that the high-pitched sound range precedes the others so as to reach the listener 9 first.
It is a general object of the present invention to provide a speaker device in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide the speaker device in which original sound and sound field information can be correctly reproduced.
In order to overcome the problems mentioned above, the present invention provides means for overcoming the problems as follows:
From a first aspect of the present invention, the above objects are achieved by a speaker device including a plurality of speakers outputting different frequency bands, wherein for a listener listening to sound from the speaker device, a first emitting direction of a first speaker emitting a high frequency band is oriented toward the listener more than a second emitting direction of a second speaker emitting a low frequency band.
According to the present invention, it is possible for the high frequency band having a shorter wavelength and a dull directivity to arrive at the listener faster than the low frequency band emitted from other speakers. Therefore, it is possible for high-pitched sound to obtain precedence.
From a second aspect of the present invention, the above objects are achieved by a speaker device including a plurality of speakers outputting different frequency bands, wherein for a listener listening to sound from the speaker device, a first emitting direction of a first speaker emitting a high frequency band is located closer to the listener than a second emitting direction of a second speaker emitting a low frequency band.
According to the present invention, it is possible for the high frequency band having a shorter wavelength and a dull directivity to arrive at the listener faster than the low frequency band emitted from other speakers. Therefore, it is possible for high-pitched sound to obtain precedence.
From a third aspect of the present invention, in the speaker device as described as the first aspect, when the speaker device is seen from a top plan view, centers of opening parts of the plurality of the speakers are aligned on a single line.
According to the present invention, by aligning acoustic centers, the listener can obtain the feeling of a natural extent of the sound.
From a fourth aspect of the present invention, in the speaker device as described as the first aspect, at least two of centers of opening parts of the plurality of the speakers have a substantially identical height.
According to the present invention, the listener can clearly recognize an orientation of the acoustic image.
From a fifth aspect of the present invention, a speaker device including a plurality of speakers outputting different frequency bands, wherein the plurality of speakers include a woofer for a low-pitched sound, a squawker for a middle-pitched sound, a tweeter for a high-pitched sound, wherein the woofer is provided upward, the squawker is provided so as to have a predetermined inclination with respect to a listener listening to sound from the speaker device, and the tweeter is positioned toward the listener and is provided at a front most of the plurality of speakers.
According to the present invention, the directional sensitivity characteristic of the speaker is considered and the higher frequency band the more the speaker is directed to a listener side. By providing the speaker emitting the high frequency band at a position closer to the listener, it is possible for the high frequency band having a shorter wavelength and a dull directivity to arrive at the listener faster than the low frequency band emitted from other speakers. Therefore, it is possible for high-pitched sound to obtain precedence.
From a sixth aspect of the present invention, in the speaker device as described as the fifth aspect, the plurality of speakers includes a ribbon tweeter outputting a frequency band identical to that output from the tweeter for the high-pitched sound, the tweeter for the high-pitched sound and the ribbon tweeter are connected in series and are provided toward an opposite direction with respect to a horn of the woofer.
According to the present invention, by using the tweeter for the high-pitched sound and the ribbon tweeter in the same frequency band, the sound pressure in the high-pitched sound is raised. Moreover, by positioning the ribbon tweeter in an opposite direction of the tweeter, the directivities of the tweeter and the ribbon tweeter can be expanded by using the direct sound waves and the reflective sound waves. Furthermore, by connecting the tweeter and the ribbon tweeter in series, the high-pitched sound is expanded and it is possible to obtain the precedence of the high-pitched sound.
From a seventh aspect of the present invention, in the speaker device as described as the fifth aspect, the squawker and the tweeter are provided at a height substantially identical to that of ears of the listener.
According to the present invention, by arranging the squawker and the tweeter at the same height position as the ears of the listener, it is possible for the high-pitched sound to obtain precedence in time measured in milliseconds. Furthermore, the listener can recognize the orientation of the acoustic image clearly.
From an eighth aspect of the present invention, in the speaker device as described as the fifth aspect, bass reflex ports are provided to the horn.
According to the present invention, the sound from the bass reflex ports and other sound from other speaker units become a single harmonized sound. Therefore, it is possible to provide a three-dimensional feeling of a sound field to the listener. Moreover, it is possible to produce howling sound by simultaneously colliding several kinds of sound with each other.